Djamel Ouis

This paper presents a systematic post-occupancy evaluation (POE) of a gated apartment building in Onaizah, Qassim, Saudi Arabia, focusing on resident satisfaction and building performance. Employing a mixed-methods approach, the research combines quantitative data from questionnaires and qualitative data from walkthrough observations and interviews to assess various performance aspects, including thermal comfort, visual comfort, acoustic performance, and safety. Results indicate that residents generally expressed satisfaction with thermal comfort, visual comfort, and indoor air quality. However, concerns were highlighted in areas such as safety and security, design adequacy, and construction support services. These findings reveal that while the building meets many occupant needs, there are critical areas requiring improvement. This study underscores the importance of incorporating POE as a valuable tool for assessing building performance and informing future design and management strategies in residential developments. Finally, this study’s methodology excelled in analyzing the quality and performance of residential building elements, which contributes to enriching the literature related to facilities management. It explains the research strategy followed to provide an organized and reliable framework that can be used to evaluate performance and quality in residential buildings.

The oil and gas (O&G) sector depends on information analysis, making digital transformation vital. Industry-specific factors like environmental, regulatory, operational, and security challenges shape its tech adoption. This paper identifies and examines the barriers and drivers of digital transformation in O&G through a literature review and expert insights, leading to a questionnaire assessment. Interpretive Structural Modeling (ISM) was employed to create a structural model that illustrates the interactions between these barriers, helping experts understand how to achieve digitization within the industry. The questionnaire analysis identified the key barriers based on their RII values: “Experiments requiring significant time for validation of new technologies”, “Technical complexities of new technologies”, “Security concerns”, “Insufficient strategies”, and “Organizational culture and resistance to change”. The ISM indicated that the “Technical complexities of new technologies” and the “Lack of readily deployable technologies” are the most influential barriers. Addressing these is crucial for O&G companies to unlock digitalization potential.

This paper presents a nondestructive testing method for assessing the structural integrity of cylindrical elements by monitoring a range of radial vibrational modes, with a specific emphasis on the so-called ovalling mode. The method involves exciting the cylinder with a single vibration source in the radial direction and measuring the response using two vibration sensors positioned diametrically on the cylinder's surface. The ovalling mode was extracted from the frequency response by adding the in-phase signals recorded by the sensors. Experiments conducted on a PVC pipe showed good agreement between the measured resonance frequency of the ovalling mode and its predicted value, calculated using the theory for thin cylindrical shells and Finite Element Method simulations. This research is an investigation into the potential and reliability of this nondestructive technique for detecting corrosion and strength-weakening defects in concrete building elements, steel pillars, and columns. The extent of the strength reduction can be determined by analyzing the change in the resonance frequency of the ovalling mode.

Cylindrical elements made of concrete or metal are found in buildings and bridges for supporting other building elements. These building elements are often exposed to environmental conditions and strength-weakening agents that may compromise their vigor and their bearing capacity. A technique or a method is therefore often desirable for controlling the health condition and integrity of these elements. Such a method is expected to be easy to implement, using light-weighted equipment, affordable and most importantly of non-destructive character. The aim of this paper is to present such a method, which is based on vibrations, and which may be used in a circular cylinder for tracking a range of vibrational modes, namely the radial ones with a prior specific emphasis on the so-called ovalling mode. This mode may be extracted from the response of the cylinder as a result of its excitation by a mechanical stress applied in the radial direction. This method uses a single concentrated source of excitation and two vibration sensors diametrically positioned and fastened onto the surface of the cylinder. The ovalling mode may then be extracted from the frequency response through adding the signals recorded by the two sensors. These two signals are in phase in the case of a test object with a circular cross-section. This study is a preliminary investigation into the feasibility and the extent of reliability of this non-destructive method when applied to the identification of corrosion or other strength-weakening agents hosted by concrete or steel pillars or columns. The degree of severity in strength loss in such elements may be assessed through an evaluation of the change in value of the resonance frequency of the ovalling mode.

The diffraction of a spherical sound wave by a thin hard half-plane is considered. The total field at any position in the space surrounding the edge of the half-plane is composed of three components, two of which are expressed from pure geometrical considerations, and a third component which seems to originate from fictive sound sources situated on the edge of the half plane. This paper takes the expression of the edge-diffracted field as formulated in the Biot-Tolstoy theory of diffraction for the case of a doublet sound signal emanating from the sound source [Biot and Tolstoy (1957). J. Acoust. Soc. Am. 29, 381–391] but rearranged later in a more tractable form by Medwin [(1981). J. Acoust. Soc. Am. 69, 1060–1064] for the more general case of a Dirac-like pulse. Hence a development in the frequency domain of the Fourier transform of the exact expression of the edge-diffracted field in the time domain takes into consideration a part with known special mathematical functions, and a part containing a serial development. This latter also expressed in some special mathematical functions, converges quite rapidly to the numerical Fourier transform of the exact time-domain expression. The presented solution may be used as a good approximation in simulations and in real case predictions of sound attenuation by thin hard barriers.